U.S. Frost Dates by Weather Station

NOAA station USC00364763 · Pennsylvania

Frost Dates near Lancaster, PA

NOAA weather station Lancaster 2 NE Filter Plant (USC00364763), Pennsylvania · elevation 270 ft (82 m) · hardiness zone 7a*

Lancaster is the nearest town to the station (1.9 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter May 7only 1 spring in 10 still has a frost later
  • Typical last frostApril 1950% chance of a frost after it
  • Typical first fall frostOctober 2450% chance of a frost before it
  • Frost-free season186 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season near Lancaster, PASpring: a frost after April 5 in 9 years out of 10, after April 19 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 24 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 186 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 19First frost ~Oct 24Frost season near Lancaster, PASpring: a frost after April 5 in 9 years out of 10, after April 19 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 24 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 186 days.JFMAMJJASONDLast frost ~Apr 19First frost ~Oct 24
frost likely chance fading 90% → 10% frost-free in a typical yearThe year at a glance. Blue: frost is likely; the gradient fades as the chance drops from 90% to 10%; green: the frost-free part of a typical year.

Frost dates (32°F)

Probability of frost, based on 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 7October 9
50% (typical)April 19October 24
90% (likely)April 5November 6
Frost-free season (32°F, 50% chance)
186 days
Hard frost (28°F), last in spring, 50% chance after
April 5
Hard frost (28°F), first in fall, 50% chance before
November 4

The last 15 years (2006–2020 normals)

Typical last frost April 19 (same as the 30-year normal), typical first fall frost October 27 (3 days later). Frost-free season 189 days.

A shorter, more recent NOAA period. The 30-year normals above remain the main reference: 15 years carry more year-to-year noise.

Add these dates to your calendar Yearly reminders for the typical last frost, the lower-risk planting date and the typical first fall frost (.ics).

How the chance of frost changes with the date

Spring near Lancaster: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 7, 20% May 2, 30% April 27, 40% April 22, 50% April 19, 60% April 17, 70% April 14, 80% April 10, 90% April 5. Observed last spring frost in recent years: 2021 April 24, 2022 April 30, 2023 April 10, 2024 March 25, 2025 April 9, 2026 April 21.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 7Apr 19Apr 52021: April 242022: April 302023: April 102024: March 252025: April 92026: April 21Fall near Lancaster: chance of a frost before this dateFall, chance of a frost before the date: 10% October 9, 20% October 15, 30% October 17, 40% October 21, 50% October 24, 60% October 27, 70% October 30, 80% November 2, 90% November 6. Observed first fall frost in recent years: 2021 November 3, 2022 October 20, 2023 November 2, 2024 October 28, 2025 October 28.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 9Oct 24Nov 62021: November 32022: October 202023: November 22024: October 282025: October 28
Two charts, because spring and fall answer different questions: in spring, the chance that a frost still comes after a date; in fall, the chance that the first frost has already come before it. NOAA publishes these odds from 10% to 90%, so the lines stop there. ◆ marks the actual date in each recent year.

What actually happened in recent years

Observed dates of the last spring and first fall frost (32°F) at this station; ◆ marks them on the charts above
YearLast spring frostFirst fall frost
2021April 24November 3
2022April 30October 20
2023April 10November 2
2024March 25October 28
2025April 9October 28
2026April 21season not over yet

What these dates mean

May 7 is the cautious spring date for the Lancaster area, and it gives a gardener the confidence to set out tender crops because only about a 10 % chance of a light frost remains after that day.

The 50 % dates – April 19 in spring and October 24 in fall – represent the point at which a light frost is equally likely to occur later (spring) or earlier (fall); they are not frost dates themselves. The hard-frost 50 % dates are April 5 in spring and November 4 in fall, and a hard frost at 28 °F can injure plants that would survive a 32 °F light frost. These probabilities are based on 28 years of NOAA normals (1991–2020).

October 9 is the cautious fall date, allowing a gardener to finish harvesting tender crops with only about a 10 % chance that a light frost has already arrived.

How to read the probabilities

The dates are probabilities from 30 years of weather, not a forecast for this year.

  • Spring: "10% after May 7" means that in about one spring out of ten a frost still happens after that date. The 90% date is the earliest: a frost after it happens in most years.
  • Fall: "10% before October 9" means that in about one fall out of ten the first frost arrives before that date.
  • 50% is the typical date: half of the years are earlier, half are later.
  • A light frost (32°F) damages tender plants; a hard frost (28°F) also stops most hardy vegetables.

Nearby weather stations

Map of weather stations near Lancaster, PANumbered nearest stations: 1 — Landisville, PA — 9 mi; 2 — New Holland, PA — 11 mi; 3 — near Oxford, PA — 21 mi; 4 — Lebanon, PA — 22 mi; 5 — near Whitfield, PA — 26 mi.NJMDDE25 mi · 40 km1. Landisville, PA — 9 mi12. New Holland, PA — 11 mi23. near Oxford, PA — 21 mi34. Lebanon, PA — 22 mi45. near Whitfield, PA — 26 mi5
  1. Landisville, PA 9 mi (15 km)
  2. New Holland, PA 11 mi (17 km)
  3. near Oxford, PA 21 mi (34 km)
  4. Lebanon, PA 22 mi (35 km)
  5. near Whitfield, PA 26 mi (42 km)

Sources

* Hardiness zone 7a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 40.05, -76.2742.